3 research outputs found

    Genetic profiling of colorectal cancer liver metastases by combined comparative genomic hybridization and G-banding analysis

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    The majority of genetic studies of colorectal carcinogenesis have focused on changes found in primary tumors. Despite the fact that liver metastases are a leading cause of colorectal cancer deaths, the molecular genetic basis of the advanced disease stages remains poorly understood. We performed comparative genomic hybridization (CGH) on 17 liver metastases from colorectal carcinomas and compared the quantitative profile with the qualitative profile previously obtained with chromosome banding. An average of 12.6 aberrations per tumor was found by CGH. Chromosome 18 and chromosome arms 4q, 8p, and 17p were most frequently lost, whereas chromosomes 7 and 20 and chromosome arms 6p, 8q, and 13q were most frequently gained. We compared the chromosome banding and CGH data after converting the karyotypes into net copy number gains and losses. Ten tumors showed agreement between the findings of the two techniques, whereas five tumors did not (in two cases, no mitotic cells were obtained for banding analysis). All five discordant cases had a "simple" abnormal or normal karyotype, but revealed multiple changes by CGH. A likely explanation for this discrepancy is that in vitro growth before G-banding selected against the cancer cells. Interestingly, by comparing the CGH profiles of the "complex" vs. the "simple"/normal karyotype groups, deletion of 8p and gain of 16q were seen more frequently in the former group. The liver metastases had the same aberrations as seen in primary colorectal carcinomas, summarized in a literature survey. However, these aberrations were seen more frequently in liver metastases, which may be attributable to increased genetic instability. (C) 2003 Wiley-Liss, Inc

    Influência do alimento na produção e qualidade do leite de cabra Influence of feed on the production on quality of goat milk

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    O leite de cabra é considerado um dos alimentos mais completos por apresentar vários elementos importantes para a nutrição humana, constituído de proteínas de alto valor biológico e ácidos graxos essenciais, além de seu conteúdo mineral e vitamínico. Esta revisão tem como objetivo avaliar as variações referentes à composição química e propriedades físicoquímicas do leite, que ocorrem em função de alguns fatores, tais como: climáticos, raça, indivíduo, estágio de lactação e alimentação. O manejo alimentar tem sido considerado um fator preponderante na manipulação dos componentes do leite. Há um entendimento dominante que a gordura é o componente do leite que mais sofre influência dos alimentos. O uso de técnicas biológicas moleculares poderá contribuir para o entendimento do mecanismo de utilização do alimento no rúmen, estabelecendo um novo cenário para a microbiologia ruminal, que pode ser diferente do que tem sido estudado até o momento.<br>Goat milk is considered one of the most complete foods, since it holds several elements which are important for human nutrition, and necessary for the constitution of tissues and blood. This revision aims to assess the variations of the chemical composition and physical-chemical properties of the milk which occur due to some factors, such as: climate, breed, the individual, lactation stage and food. Feed management has been considered a key factor in the manipulation of milk components. There is a general understanding that among the components of the milk fat is the most influenced by food. The use of molecular biological techniques might contribute to the understanding of the mechanism of utilization of food in rumen, establishing a new possibility for ruminal microbiology, which can be different from what has been studied so far
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